Patent GB-157394-A (GB)
Title: Improvements in and relating to embroidering machines
IPC: D05C11/08
Filed: 1921-01-10
Abstract: 157,394. Fahrni, O. Nov. 10, 1919, [Convention date]. Embroidery machines. - In a Heilmann type embroidery machine, the needle-carriages have a short stroke of constant amplitude and the threads are tightened in the work by take-up frames the stroke of which is diminished for each stitch by an amount corresponding to the thread absorbed in the preceding stitch. Needles, driving.-The needles 23 are clamped between fixed arms 20, Fig. 6, and projections 21 on sleeves 18. All the sleeves of one needlecarriage are actuated simultaneously to clamp the needles, by a rod 25 which is linked to a rod 30 also mounted on the carriage. As the carriage is moved up to the work frame, a slot 33, Fig. 4<a>, in the end of the rod 30 is passed over a pin on a lever 34 and, that lever being then actuated by a cam, the needle-clamps are closed. A latch 43 locks the rod 30 so that the needle-clamps remain closed when the carriage is moved away and when the carriage is moved forward again the latch is removed by a rod 45 which is raised by a cam. Take-up devices.-The take-up frames are raised and lowered by means of cords passing over pulleys 59, 62 mounted freely on either side of a spur-wheels 64. The pulleys are rotated clockwise into the same positions in each cycle by means of connecting-rods and cam-actuated rods 70 but the rods 70 are returned by springs and the pulleys move backward only so far as is determined by the position of pins 68 on the wheel 64 with which pins on the pulleys engage. The wheel 64 is given a forward movement corresponding to the amount of thread absorbed in the preceding stitch by means of a ratchet wheel 78 which is rotated step by step by means of a pawl 80, Fig. 3. The pawl is moved backwards positively by a lever 79 and cam gear 101, 102, 103 and is moved forward up to a pin 98 by a spring 99. The pin 98 is carried by a sector 81 which is positioned in each cycle by jacquard mechanism and is then locked by a detent 100. The jacquard mechanism includes a cord 83 secured to the sector and passing over pulleys 93 on a series of levers 89 of different lengths. The levers 89 are held in the position shown by pins 86 which rest upon a pattern card. In accordance with the thread absorbed in the last stitch, certain of the pins fall into perforations in the pattern card and the cord 83 which is held taut by the spring 97, Fig. 3, pulls the corresponding levers 89 inwards and the sector 81 moves through a distance equal to the sum of the distances corresponding to the several levers moved. Levers 106 and pins 107 are used to return the levers 89 to their initial positions. The movement of the wheel 64 through a quadrant corresponds to the whole length of the needle-thread. Accordingly four pins 68 are provided on each side of the wheel 64 and at the completion of a quarter of a revolution, when the needles are re-threaded, outer pins 69 engage wedge-pieces 73, Fig. 2, force them and the levers 75 carrying them outwards and thereby move the pulleys 59, 62 away from the wheel 64 so that the pins 68 can pass the pins 62. The pulleys are immediately returned and the sequence of movements recommences.